> type:1\-所有空格2\-前后空格3\-前空格4\-后空格 ``` export const trim = (str, type) => { type = type || 1 switch (type) { case 1: return str.replace(/\s+/g, ""); case 2: return str.replace(/(^\s*)|(\s*$)/g, ""); case 3: return str.replace(/(^\s*)/g, ""); case 4: return str.replace(/(\s*$)/g, ""); default: return str; } } ```